As for what led to the violent altercation, Radar reveals the argument had to do with Tamra planning a birthday party for one of their kids at her house. Despite inviting Simon to the party, he apparently felt she should have chosen a more neutral location.

The altercation took place Monday night as Simon was returning their small dog back to Tamra’s house (the two share custody of the dog). A source tells Radar that Simon “was angry and threw the leash at her and hit her with it.” The source adds that “their kids were in the house and started crying. It was a bad scene.”

Tamra, who has been dating Eddie Judgefor months now, felt that Simon went too far. “The leash hit Tamra. She wasn’t sure what to do,” says the source. “But she knew she couldn’t tolerate the violence. She called the cops.”

Simon is scheduled to be arraigned today. He is expected to enter a plea to the charge. TMZ is also reporting that Simon is still in police custody. His mugshot is below. The sixth season of the Real Housewives of OC is currently filming, though Simon will no longer be a part of the show.